Don't print the entire declaration of the alliassee when `->toChars()` is called on an `AliasDeclaration`; just printing the name will do. This fixes #305, which otherwise tries to generate {{{ class E { void A() { alias /* recurse into E->toCBuffer() */ m; } } }}} by way of an infinite recursion (causing a segfault when the stack runs out).

module tangotests.mem5;

class SC
{
    int* ip;
    this()
    {
        ip = new int;
    }
    ~this()
    {
        delete ip;
    }
    void check()
    {
        assert(ip !is null);
    }
}

void main()
{
    scope sc = new SC;
    sc.check();
}